How find out if the PCIe is PCIe or PCIe ?

PCI-E and PCI-X Card Guidelines ; 1UXXL PCI-X Full height, half length · 133 MHz ; 1UEEL PCI-E Full height, half

The smallest PCIe slot will run at x1 speed, while a full-size PCIe slot will run at x16 PCIe x16 slots are generally intended for use with Graphics Cards

pcie4 slot PCIe adapters and slots come in 4 different sizes: 1x, 4x, 8x, and 16x Smaller size adapters do fit in larger slots, but larger size adapters do not fit in

pciex16 slot PCI Express x16 — Sixteen lanes, largest slot *some slots may not have matching lanes in bandwidth, more on this throughout the article